In the fields of biology and medicine, there is often a need for high throughput analysis and sorting of particles. One well known technique for sorting particles is droplet deflection. See, for example, U.S. Pat. No. 6,372,506. In droplet deflection a stream of suspended particles is broken into individual droplets, for example, using a piezoelectric mechanism. At the point of droplet formation, an electrical charging element is used to selectively charge each droplet. The charged droplet then free falls through an electrostatic field which deflects the charged particle into one of a plurality of receiving containers.
Another technique for deflecting particles involves utilizing switching or pressure mechanisms to divert a volume of fluid containing a particle into a selected branch channel of a flow-path defined on a microfluidic chip. See, for example, U.S. Pat. No. 6,808,075, which is hereby incorporated, herein, in its entirety.